da02			#jump past constants
07f0			#exception state location
07f5			#serial port register

#load exception state location
0200			#set r0 to the address of the constant
0146			#load from r0 into r0 -- r0 is 7f0
0146			#load from exception state register and clear flag

#shift left ignoring carry until tty is high bit
1987			#now exec is high
1987			#now nmi is high
1987			#now rtc is high
1987			#now disk is high
1987			#now tty is high

#get the value of this bit into the flag
198f			#have the flag set

#if the flag is clear, go to 0
dbf5			#if flag set, decrement by 10

#we had a write! load tty location
0201			#r0 is the address of address of tty
0146			#r0 is the serial port address
2146			#copy address to r1
2546			#load the byte into r1
0684			#write r1 to (r0) and clear flag

#loop! go to address 3
da02			#do the loop
